1. Field of the Invention
The invention relates generally to a method for topically treating inflammation in humans or animals. More particularly, the invention relates to a method of treating inflammation in humans and animals with acetylsalicylic acid esters.
2. Background of the Prior Art
Acetylsalicylic acid or aspirin, as it is commonly known, is well known in the art. Alkyl and aralkyl esters of acetylsalicylic acid also are known in the prior art. For example, methyl acetylsalicylate is disclosed in U.S. Pat. No. 3,119,739 as an anodyne agent useful in alleviating pain associated with insect bites. The Merck Index, 9th ed., discloses that methyl acetylsalicylate also is used as a fixative for perfumes. U.S. Pat. No. 2,113,374 discloses salicylic acid derivatives of polyhydric alcohols useful as topically active analgesics and antirheumatics. U.S. Pat. No. 4,126,681 discloses multiple uses of non-acetylated salicylates in topical preparations for the treatment of inflammation including acne and also discloses a topical composition containing acetylsalicylic acid combined with topical components to enhance penetration of the skin of the acetylsalicylic acid. As discussed in U.S. Pat. No. 4,126,681, the anti-inflammatory response of tissue to acetylsalicylic acid, as well as skin irritating properties of acetylsalicylic acid, has been recognized. However, the delivery of acetylsalicylic acid to the skin in a form which can be readily absorbed by the skin and is not irritating to tissues has not been satisfactorily solved by the prior art.